The present invention relates to a triplebasic propellant powder comprising nitrocellulose (NC), nitroglycerin (NGL) or an equivalent explosive oil and crystalline nitroguanidine (NIGU), which can be processed to solid propellant bodies by mixing with one another, plastioizing the NC by means of a solvent, e.g. acetone, as well as kneading the mixture.
Compared with singlebasic and doublebasic prepellant powders, triplebasic propellant powders have the advantage of high power but limited barrel erosion, these characteristics mainly being due to the nitroguanidine content. This can range from 5% to over 50% by weight, reference being made e.g. to types M30, M31, NQ and MNF for the range between 45 and 53% by weight. These propellant powders are either processed discontinuously in kneaders or continuously in oxtrudoro to shaped bodies and in the latter case to propellant strands, which can then be cut to give bodies from which the propellant charges are prepared. Plasticizing and therefore shapability are mainly determined by the nitrocellulose content which, as a result of the solvent, e.g. acetone acquires a gel structure and binds in the other components.
The mechanical strength and in particular the brittleness behaviour is decisively influenced by the nitroguanidine mixed in in crystalline form. Particularly at low temperatures, it has an increased cold embrittlement tendency, even at conventional temperatures of use down to -40.degree. C. When firing such propellant powders, particularly those with a high NIGU proportion, the cold embrittlement leads to very unfavourable interior ballistics, which can even make the powder unusable.